1. Field of the Invention
The present invention relates to an electronic control unit (ECU) for a vehicle, and more particularly relates an ECU that manages a change of vehicle identification information.
2. Description of Related Art
A modern vehicle is equipped with multiple electronic control units (ECUs) for controlling parts of the vehicle. As described in JP-A-2001-301572 for example, an engine ECU, which is one of the ECUs, stores a vehicle identification number (VIN) in a memory thereof such as an EEPROM or the like. The VIN is unique on a vehicle-by-vehicle basis and can function as vehicle identification information. In addition to the VIN, the engine ECU stores immobilizer identification information (e.g., immobilizer ID), various types of malfunction information, learning data for vehicle control and the like in the memory.
When an ECU that stores a VIN is detached from one vehicle and re-mounted in a different vehicle, it is necessary to change the VIN to one that is proper to the different vehicle.
However, when a change of a VIN stored in an ECU is freely permitted upon reception of an instruction for changing the original VIN, a disadvantage arises. For example, even when an ECU is mounted in one vehicle and is not re-mounted in a different vehicle, it is possible change the stored VIN to a different one that does not meet the one vehicle. Since VINs are used to uniquely identify vehicles, the above-described disadvantage can lead to, for example, an improper change of a VIN.